Along with recent developments in techniques for reducing the size of semiconductors and increasing the speed thereof, the amount of data communicated between devices or LSIs in the devices tends to increase more and more. However, there are strict restrictions on the number of LSI terminals (pads) as the number affects package cost.
Communication modes used under such restrictions include the half-duplex communication mode and the full-duplex communication mode. The half-duplex communication mode requires a directional control of transmission and reception and an arbitration of a transmission right, whereas the full-duplex communication mode enables data to be transmitted and received simultaneously.
Patent literatures 1 and 2 disclose techniques for effectively transmitting and receiving data targeted for processing (hereinafter, target data), by switching between the full-duplex communication mode and the half-duplex communication mode.
For example, Patent literature 1 discloses a technique for switching the communication mode to the half-duplex communication mode when performing either transmission or reception, and to the full-duplex communication mode when performing both transmission and reception.
Patent literature 2 discloses a technique for, when switching to the half-duplex communication mode, performing (i) a directional control of transmission and reception and (ii) bit synchronization after the directional control, with use of a special control code defined by an encoding scheme such as 8b/10b.